... The last contested Republican and Democratic Conventions were in 1948 and 1952, respectively, and both nominated a candidate on the third ballot. The 1924 Convention went to the hundred-and-third ballot, before rejecting both front-runners, former Treasury Secretary William McAdoo, of California, and Governor Al Smith, of New York. It has lately drawn attention as an extreme example of what Politico has called “conventional chaos.” What tore the Convention apart, however, wasn’t choosing a nominee, or even Prohibition, divisive as the fight between the drys and the wets (many of them wicked New Yorkers) had been. It was another question, one that Trump’s candidacy has brought back to the fore: whether, and how strongly, to disavow the Ku Klux Klan.

McAdoo, who was married to President Woodrow Wilson’s daughter, had positioned himself as the enemy of New York and of Wall Street, even though, as a lawyer and a businessman, he had made a good deal of money there. (Apparently, he hadn’t made enough: during the campaign, it emerged that he’d been on a twenty-five-thousand-dollar retainer from an oil man implicated in the Teapot Dome scandal.) As Robert Murray notes in “The 103rd Ballot,” the standard history of the Convention, the Klan was then in the midst of a major revival, and McAdoo wanted its support.

But Senator Oscar Underwood, an anti-Klan Alabamian, pushed to include a plank in the Party platform condemning the group, declaring that “it is just a question of being brave and facing the issue squarely.” Smith, a Catholic despised by the Klan, favored Underwood’s plank. McAdoo deployed his supporters to defeat it in a late-night floor fight that included actual wrestling and punching. It was defeated by a handful of votes. Afterward, thousands of Klansmen paraded in New Jersey, where one speaker called New York a “foreign country.” ...

[HNN Editor: While McAdoo succeeded in defeating the anti-KKK plank, he lost his bid for the nomination. On the 103rd ballot John Davis, an obscure figure in the party, was the compromise choice of the convention.]

... What if McAdoo, with his opportunistic turn to nativism, had won the nomination, having cemented the Klan’s institutional place in the Party? What would the political alternatives to Hooverism have looked like when the Depression awakened the country’s deepest fears? ...